<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    .running {
      width: 100px;
      height: 30px;
      background-color: transparent;
      background-image: repeating-linear-gradient(
        -45deg,
        red,
        red 5px,
        blue 5px,
        blue 10px
      );
      background-position-x: 100px;
      background-size: 6000px 800px;
      animation: background-run 450s infinite linear;
    }

    @keyframes background-run {
      from {
        background-position-x: 100px;
      }
      to {
        background-position-x: 6000px;
      }
    }
  </style>
  <body>
    <div class="running"></div>
  </body>
</html>
